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Scrape information from Web Pages with Java?

I'm trying to extract data from a webpage, for example, lets say I wish to fetch information from chess.org.
I know the player's ID is 25022, which means I can request
http://www.chess.org.il/Players/Player.aspx?Id=25022
In that page I can see that this player's fide ID = 2821109.
From that, I can request this page:
http://ratings.fide.com/card.phtml?event=2821109
And from that I can see that stdRating=1602.
How can I get the "stdRating" output from a given "localID" input in Java?
(localID, fideID and stdRating are aid parameters that I use to clarify the question)

You could try the univocity-html-parser, which is very easy to use and avoids a lot of spaghetti code.
To get the standard rating for example you can use this code:
public static void main(String... args) {
UrlReaderProvider url = new UrlReaderProvider("http://ratings.fide.com/card.phtml?event={EVENT}");
url.getRequest().setUrlParameter("EVENT", 2821109);
HtmlElement doc = HtmlParser.parseTree(url);
String rating = doc.query()
.match("small").withText("std.")
.match("br").getFollowingText()
.getValue();
System.out.println(rating);
}
Which produces the value 1602.
But getting data by querying individual nodes and trying to stitch all pieces together is not exactly easy.
I expanded the code to illustrate how you can use the parser to get more information into records. Here I created records for the player and her rank details which are available in the table of the second page. It took me less than 1h to get this done:
public static void main(String... args) {
UrlReaderProvider url = new UrlReaderProvider("http://www.chess.org.il/Players/Player.aspx?Id={PLAYER_ID}");
url.getRequest().setUrlParameter("PLAYER_ID", 25022);
HtmlEntityList entities = new HtmlEntityList();
HtmlEntitySettings player = entities.configureEntity("player");
player.addField("id").match("b").withExactText("מספר שחקן").getFollowingText().transform(s -> s.replaceAll(": ", ""));
player.addField("name").match("h1").followedImmediatelyBy("b").withExactText("מספר שחקן").getText();
player.addField("date_of_birth").match("b").withExactText("תאריך לידה:").getFollowingText();
player.addField("fide_id").matchFirst("a").attribute("href", "http://ratings.fide.com/card.phtml?event=*").getText();
HtmlLinkFollower playerCard = player.addField("fide_card_url").matchFirst("a").attribute("href", "http://ratings.fide.com/card.phtml?event=*").getAttribute("href").followLink();
playerCard.addField("rating_std").match("small").withText("std.").match("br").getFollowingText();
playerCard.addField("rating_rapid").match("small").withExactText("rapid").match("br").getFollowingText();
playerCard.addField("rating_blitz").match("small").withExactText("blitz").match("br").getFollowingText();
playerCard.setNesting(Nesting.REPLACE_JOIN);
HtmlEntitySettings ratings = playerCard.addEntity("ratings");
configureRatingsBetween(ratings, "World Rank", "National Rank ISR", "world");
configureRatingsBetween(ratings, "National Rank ISR", "Continent Rank Europe", "country");
configureRatingsBetween(ratings, "Continent Rank Europe", "Rating Chart", "continent");
Results<HtmlParserResult> results = new HtmlParser(entities).parse(url);
HtmlParserResult playerData = results.get("player");
String[] playerFields = playerData.getHeaders();
for(HtmlRecord playerRecord : playerData.iterateRecords()){
for(int i = 0; i < playerFields.length; i++){
System.out.print(playerFields[i] + ": " + playerRecord.getString(playerFields[i]) +"; ");
}
System.out.println();
HtmlParserResult ratingData = playerRecord.getLinkedEntityData().get("ratings");
for(HtmlRecord ratingRecord : ratingData.iterateRecords()){
System.out.print(" * " + ratingRecord.getString("rank_type") + ": ");
System.out.println(ratingRecord.fillFieldMap(new LinkedHashMap<>(), "all_players", "active_players", "female", "u16", "female_u16"));
}
}
}
private static void configureRatingsBetween(HtmlEntitySettings ratings, String startingHeader, String endingHeader, String rankType) {
Group group = ratings.newGroup()
.startAt("table").match("b").withExactText(startingHeader)
.endAt("b").withExactText(endingHeader);
group.addField("rank_type", rankType);
group.addField("all_players").match("tr").withText("World (all", "National (all", "Rank (all").match("td", 2).getText();
group.addField("active_players").match("tr").followedImmediatelyBy("tr").withText("Female (active players):").match("td", 2).getText();
group.addField("female").match("tr").withText("Female (active players):").match("td", 2).getText();
group.addField("u16").match("tr").withText("U-16 Rank (active players):").match("td", 2).getText();
group.addField("female_u16").match("tr").withText("Female U-16 Rank (active players):").match("td", 2).getText();
}
The output will be:
id: 25022; name: יעל כהן; date_of_birth: 02/02/2003; fide_id: 2821109; rating_std: 1602; rating_rapid: 1422; rating_blitz: 1526;
* world: {all_players=195907, active_players=94013, female=5490, u16=3824, female_u16=586}
* country: {all_players=1595, active_players=1024, female=44, u16=51, female_u16=3}
* continent: {all_players=139963, active_players=71160, female=3757, u16=2582, female_u16=372}
Hope it helps
Disclosure: I'm the author of this library. It's commercial closed source but it can save you a lot of development time.

As #Alex R pointed out, you'll need a Web Scraping library for this.
The one he recommended, JSoup, is quite robust and is pretty commonly used for this task in Java, at least in my experience.
You'd first need to construct a document that fetches your page, eg:
int localID = 25022; //your player's ID.
Document doc = Jsoup.connect("http://www.chess.org.il/Players/Player.aspx?Id=" + localID).get();
From this Document Object, you can fetch a lot of information, for example the FIDE ID you requested, unfortunately the web page you linked inst very simple to scrape, and you'll need to basically go through every link on the page to find the relevant link, for example:
Elements fidelinks = doc.select("a[href*=fide.com]");
This Elements object should give you a list of all links that link to anything containing the text fide.com, but you probably only want the first one, eg:
Element fideurl = doc.selectFirst("a[href=*=fide.com]");
From that point on, I don't want to write all the code for you, but hopefully this answer serves as a good starting point!
You can get the ID alone by calling the text() method on your Element object, but You can also get the link itself by just calling Element.attr('href')
The css selector you can use to get the other value is
div#main-col table.contentpaneopen tbody tr td table tbody tr td table tbody tr:nth-of-type(4) td table tbody tr td:first-of-type, which will get you the std score specifically, at least with standard css, so this should work with jsoup as well.

Extract a JavaScript line from a website's sourcecode using JSoup

I have this JavaScript sourcecode from a website.
<script>"#context": "http://schema.org/","#type": "Product","name": "Shower head","image": "https://example.com/jpeg.png","description": "Hello stackoverflow","url": "link.com","offers": {"#type": "Offer","priceCurrency": "USD","price": "10.00","itemCondition": "http://schema.org/NewCondition","availability": "http://schema.org/InStock","url": "MyUrl.com","availableAtOrFrom": {"#type": "Place","name": "Geneva, NY","geo": {"#type": "GeoCoordinates","latitude": "42.8361","longitude": "-76.9874"}},"seller": {"#type": "Person","name": "Edward"}}}</script>
And I'm trying to use this JSoup code to extract the last line with "name": "Edward"
public class JsoupCrawler {
public static void main(String[] args) {
try {
Document doc = Jsoup.connect("https://example.com").userAgent("mozilla/17.0").get();
Elements temp = doc.select("script.name");
int i=0;
for (Element nameList:temp) {
i++;
System.out.println(i+ " "+ nameList.getElementsByTag(" ").first().text() );
}
}
catch (IOException e) {
ex.printStackTrace();
}
}
}
Can somebody help me with this, or is impossible?

JSoup is interpreting HTML. The Contents of the <script> element contain JavaScript, so JSoup can't interpret what is inside the <script> element.
It looks as if the content of the <script> element is formatted in JSON. So you could use JSoup to get to the content of the <script> element, and then try to feel this string into a JSON interpreting library. Look here if you want to dive into that: How to parse JSON in Java
If this is a one-off and you can trust that the contents of the <script> element do not change too much, you may also use regular expressions to get to the desired part. However, I would recommend using a JSON library.

How to extract the next tag elements in jsoup

I am using jsoup to parse html document . I need the value of P tag just after the SPAN tag which contains id attribute.
I am trying with the following code
Elements spanList = body.select("span");
if (spanList != null) {
for (Element element1 : spanList) {
if (element1.attr("id").contains("midArticle")) {
Element element = element1.after("<p>"); // This line is wrong
if (element != null) {
String text = element.text();
if (text != null && !text.isEmpty()) {
out.println(text);
}
}
}
}
}
The html sample code
<span id="midArticle_9"></span>
<p>"The Director owes it to the American people to immediately provide the full details of what he is now examining," Podesta said in a statement. "We are confident this will not produce any conclusions different from the one the FBI reached in July." </p>
<span id="midArticle_10"></span>
<p>Clinton has repeatedly apologized for using the private email server in her home instead of a government email account for her work as secretary of state from 2009 to 2013. She has said she did not knowingly send or receive classified information.</p>

i hope this resolves your issue...
public static void main(String[] args) {
String html = "<span id=\"midArticle_9\"></span><p>\"The Director owes it to the American people to immediately provide the full details of what he is now examining,\" Podesta said in a statement. \"We are confident this will not produce any conclusions different from the one the FBI reached in July.\" </p><span id=\"midArticle_10\"></span><p>Clinton has repeatedly apologized for using the private email server in her home instead of a government email account for her work as secretary of state from 2009 to 2013. She has said she did not knowingly send or receive classified information.</p>";
Document document = Jsoup.parse(html);
Elements elements = document.getElementsByTag("span");
for (Element element : elements) {
System.out.println(element.nextElementSibling().text());
}
}

Java - Getting HTTP error 503 when querying google

I'm trying to code a little program in Java, with a small UI, that lets you use some google search's keyword to improve your search.
I have 2 text field (one for the site and one for the keywords) and 2 date pickers to let the user select the date range for the searching result .
When I press the search button it will connect to the following url:
"https://www.google.it/search?q=" + site + Keywords + daterange
site = "site:SITE_MAIN_URL"
keywords are the keywords i am looking for
daterange = "daterange:JULIAN_DATE_1 - JULIAN_DATE_2"
after all this I fetch the first 10 result, but here's the problem...
If I select no dates I can easily fetch the links
If I set the daterange I get the HTTP 503 error that is the one for service unavailable (if I paste the generated URL on my web browser everything works fine)
(the User Agent is set to mozilla 5.0)
EDIT: didn't post any code :P
//here i generate the site
site = "site:" + website_field.getText();
//here i convert the dates using a class found on the net
d1 = (int) DateLabelFormatter.dateToJulian(date1);
d2 = (int) DateLabelFormatter.dateToJulian(date2);
daterange += "+daterange:" + d1 + "-" + d2;
//here i generate the keywords
keywords = keyword_field.getText();
String[] keyword = keywords.split(" ");
for (int i = 0; i < keyword.length; i++) {
tempKeyword += "+" + keyword[i];
}
//the query
query = "https://www.google.it/search?q=" + site + tempKeyword + daterange;
//the connection (wrapped in a try-catch)
Document jSoupDoc = Jsoup.connect(query).userAgent("Mozilla/5.0").timeout(5000).get();
//fetching the links
Elements links = jSoupDoc.select("a[href]");
Element link;
for (int i = 0; i < links.size(); i++) {
link = links.get(i);
String temp = link.attr("href");
// filtering the first 10 google links
if (temp.contains("url")) //donothing
if (temp.contains("webcache")) { //donothing
} else {
String[] splitTemp = temp.split("=");
String[] splitTemp2 = splitTemp[1].split("&sa");
System.out.println(splitTemp2[0]);
}
}
After executing all this (NotSoWellWritten)code if i select no date, and i use just the "site" and the "keywords" I can see on the console the first 10 result found on the google search page.
If i select a daterange from the datepickers i get the 503 error.
If you wanna try a working query, here's one that search on facebook.com the keyword "dog" starting from the 1st of november to the 15th generated with this "tool"
https://www.google.it/search?q=site:facebook.com+dog+daterange:2457328-2457342
`

I have no problems using the following code:
import java.io.IOException;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class Main
{
public static void main(String[] args) throws IOException
{
// the connection (wrapped in a try-catch)
Document jSoupDoc = Jsoup.connect("https://www.google.it/search?q=site:facebook.com+dog+daterange:2457328-2457342").userAgent("Mozilla/5.0").timeout(5000).get();
// fetching the links
Elements links = jSoupDoc.select("a[href]");
Element link;
for (int i = 0; i < links.size(); i++)
{
link = links.get(i);
String temp = link.attr("href");
// filtering the first 10 google links
if (temp.contains("url") && !temp.contains("webcache"))
{
String[] splitTemp = temp.split("=");
String[] splitTemp2 = splitTemp[1].split("&sa");
System.out.println(splitTemp2[0]);
}
}
}
}
The code gives this as output on my computer:
https://www.facebook.com/uniladmag/videos/1912071728815877/
https://it-it.facebook.com/DogEvolutionAsd
https://it-it.facebook.com/DylanDogSergioBonelliEditore
https://www.facebook.com/DelawareCountyDogShelter/
https://www.facebook.com/LostDogAlert/
https://it-it.facebook.com/pages/Toelettatura-Vanity-DOG/270854126382923
https://it-it.facebook.com/washdogsgm
https://www.facebook.com/thedailystar/videos/1193933410623520/
https://www.facebook.com/OakhurstDogPark/
https://www.facebook.com/bigdogdinerco/
A 503 error usually means that the web server is having temporary issues. Specifically:
503: The Web server (running the Web site) is currently unable to handle the HTTP request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition which will be alleviated after some delay.
If this code works but your original code still does not, then your code is not generating the URL you posted and you should investigate further.

Besides the coding style, I don't see any functional problems with the provided code and it supplies the answers correctly (tested it locally). The problem might reside in the dateToJulian which I don't know what it returns and how the result is cast to int (if information is lost).
Also, consider the case in which the keywords contain dangerous characters and they are unescaped. They should be sanitized beforehand.
Another possibility is that Google is rejecting your queries if you are sending too many too fast. If this was done using a visual browser, you'd get a "We want to make sure you're not a robot." and a CAPTCHA page. That is why I'd recommend leveraging the Google API for your searches. See this SO for more info: How can you search Google Programmatically Java API

Cannot download full Document using HtmlUnit and Jsoup combination (using Java)

Problem Statement:
I want to crawl this page : http://www.hongkonghomes.com/en/property/rent/the_peak/middle_gap_road/10305?page_no=1&rec_per_page=12&order=rental+desc&offset=0
Lets say I want to parse the address, that is "24, Middle Gap Road, The Peak, Hong Kong"
What I did:
I first only tried to load using jsoup, but then I noticed that the page is taking some time to load. So, then I also plugged in HTMLUnit to wait for the page to load first
Code I wrote:
public static void parseByHtmlUnit() throws Exception{
String url = "http://www.hongkonghomes.com/en/property/rent/the_peak/middle_gap_road/10305?page_no=1&rec_per_page=12&order=rental+desc&offset=0";
WebClient webClient = new WebClient(BrowserVersion.FIREFOX_38);
webClient.waitForBackgroundJavaScriptStartingBefore(30000);
HtmlPage page = webClient.getPage(url);
synchronized(page) {
page.wait(30000);
}
try {
Document doc = Jsoup.parse(page.asXml());
String address = ElementsUtil.getTextOrEmpty(doc.select(".addr"));
System.out.println("address"+address);
} catch (Exception e) {
e.printStackTrace();
}
}
Expected output :
In the console, I should get this output:
address 24, Middle Gap Road, The Peak, Hong Kong
Actual output :
address

How about this?
final Document document = Jsoup.parse(
new URL("http://www.hongkonghomes.com/en/property/rent/the_peak/middle_gap_road/10305?page_no=1&rec_per_page=12&order=rental+desc&offset=0"),
30000
);
System.out.println(document.select(".addr").text());